With indexed number series, we start with zero and count up e.g. 0, 1, 2, 3, …
Also we read from left to right, top to bottom.

Strings are an array of chars, and an Array begins with 0 and goes up to (n - 1) where n is equal to the length of the array. e.g. [0, 1, 2, 3…, n - 1]. Each char has an index number that matches it’s placement in the order of it’s position.

Let’s say you had a string, var myString = "FOO BAR" then you would have 7 different chars in order from left to right. Sense you start counting from zero you would represent the placement of each char as 0 = F, 1 = O, 2 = O, 3 = //whitespace, 4 = B, 5 = A, 6 = R.

One way to access a char value is to use [ square brackets ] at the end of a String the same way you would with accessing values from any Array. e.g.